SSTDR can be used to detect faults in many types of electrical networks. SSTDR typically involves a) transmitting a signal into the electrical network under test (e.g., transmitting a pseudo random binary signal modulated sine wave through a transmission line), b) detecting the reflected signal, and c) identifying impedance mismatches in the electrical network by, inter alia, autocorrelation between the transmitted signal(s) and the reflected signal(s). This approach, however, breaks down when applied to PV electrical systems that comprise large numbers of interconnections and impedance mismatches. As used herein, a PV electrical system or PV electrical network refers to an electrical system comprising photovoltaic elements, such as solar panels, solar cells, PV strings, and/or the like.
The procedure for finding faults in a PV system may require numerous manual isolation and measurement steps. At each step of the procedure, the current flow within a respective subsection of the PV system is checked by a) isolating the subsection, and b) evaluating the subsection by, inter alia, acquiring one or more of open-circuit voltage (VOC) measurement(s), positive-to-ground current measurement(s), and negative-to-ground current measurement(s). The measurements may require the subsection of the PV system to be online (e.g., be receiving electro-optical (EO) radiation, such as sunlight), and may further involve the use of irradiance and/or temperature sensors to evaluate the functionality of the PV subsection. Moreover, after fault testing, the PV system has to be restored, which may involve reconnecting the subsections of the PV system, and validating the corresponding connections. Therefore, improved mechanisms for detecting fault conditions in electrical networks, such as PV systems, are needed.
In the following description, numerous specific details are provided for a thorough understanding of the various embodiments disclosed herein. However, those skilled in the art will recognize that the systems and methods disclosed herein can be practiced without one or more of the specific details, or with other methods, components, materials, etc. In addition, in some cases, well-known structures, materials, or operations may not be shown or described in detail in order to avoid obscuring aspects of the disclosure. Furthermore, the described features, structures, or characteristics may be combined in any suitable manner in one or more alternative embodiments.